Experimental cancer drug reverses debilitating bone disease and stops midlife weight gain, scientists discover

Scientists have discovered an experimental drug that could be used to treat crippling bone loss and weight gain in mid and later life.About one in five women aged 50 and over has osteoporosis, a painful condition where bones weaken, raising the risk of fractures in the hip, wrist or spine.Drugs are available to strengthen bones, but they cause a litany of unpleasant side effects, including hot flashes, leg cramps and swelling. Some must also be taken standing, with patients told to stay upright for 30 minutes afterwards.Now, researchers in the UK and Maryland say they have found a potential alternative that works without the major side effects.The drug, called CADD522, was developed to treat cancers including bone cancer and works by blocking a protein that drives tumor growth and spread. But scientists found that when postmenopausal mice were given the drug for eight weeks, they developed much stronger bones. They also lost weight compared to those that did not receive the drug. The drug was well tolerated, even after it was also given to rats and dogs. It is still in the early stages of development and likely years away from reaching patients, but researchers said the finding could lead to a 'new generation of osteoporosis treatments'. About four in five osteoporosis patients are women. Drugs are available but they have grueling side effects. Now, researchers say they have potentially found a new treatment Dr Darrell Green, a biomedical scientist at the University of East Anglia who led the study, said: 'We have uncovered an entirely new way of tackling [osteoporosis].'We hope our work could lead to a new generation of osteoporosis treatments that tackle bone loss while also addressing some of the wider metabolic consequences of menopause.'About 10 million Americans have osteoporosis, estimates suggest, which often is not diagnosed until someone suffers from a bone break. About 44 million have osteopenia, its precursor and a low bone density that also raises the risk of fractures.Bones are normally dense and strong enough to support someone's weight and absorb most impacts, but from about 35 years old, they begin to weaken, raising the risk of injury.Women over 50 are particularly at risk because menopause triggers fluctuations in hormones that speed bone loss and cause bones to weaken significantly.Those who are naturally thin, smoke, are not physically active or drink alcohol regularly are also considered to be at higher risk of suffering from the condition.Celebrities diagnosed with the condition include Ellen DeGeneres, who revealed her condition in 2024. In 2010, Gwyneth Paltrow revealed that at just 37 years old she had been diagnosed with osteopenia. Gwyneth Paltrow revealed in 2010 that she had been diagnosed with osteopenia, or weakened bones. The condition is a precursor to osteoporosisIn tests, the experimental drug worked by blocking the RUNX2 gene, which makes a protein that can fuel cancer growth but is also critical for developing and maintaining teeth, bones and cartilage. It was not clear why blocking the protein boosted bone growth after menopause, but researchers said it may be the case that the protein actually slows bone growth if hormones are also fluctuating.In the study, published in npj Drug Discovery, mice had their ovaries removed to trigger menopause and were then administered the drug for eight weeks.At the end of the period, scans showed mice that received the drug had improved bone volume over those who did not get the drug. They also had better preservation of the honeycomb-like structures inside bones that give them their strength.Blood tests showed that the drug had stimulated new bone growth in mice that received it. Researchers were also surprised to find that mice which received the drug weighed less at the end of the experiment than those who did not receive it.It was not clear why this was the case, but researchers said it suggested the drug may also help fuel weight loss. In a test on human tissue, the team also found that the drug was broken down more slowly, which they said could boost its performance.Green added: 'This is still in the early stages and has so far only been tested in animals, but we hope that the benefits will translate to humans to ultimately reduce fracture rates.'